SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dda1b896703e820c8da093629553902e06b05b500ed70a90ae997a92c2502ea3' 
  AND token = 'E0qenphIcXGMgw2NlxqDm8sbJK2kiNjgSwR5P4TgcuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}